Disazo naphthopyridine dyes



- acid solution, with any the dyes are to materials, it is preferable that both the diazo component and the coupling component be free Patented July 31, 1945.

England, asslgllor to British Oelanese Inindon, a company of Great Britain No Drawing Application November 21,1942, Se- H 468,475. In- Great Britain January 2,

This invention relates to the production of azo dyes and to the eolouration therewith ofltextile and other materials,- particularly materials containing organic esters and ethers of cellulose.

Accordingto the invention valuable disazo dyes are obtained by coupling a diazotised aromatic amino-azo compound with a 7-hydroxy-1:2:3:4-

tetrahydronaphthopyridine. The invention includes the manufacture of the dyes, the dyes themselves which are disaso dyes having a '7- hydroxy-1:2:3:4 tetrahydronaphthopyridine as end component, compositions containing the dyes together with other substancea'e. g. dispersing agents, pr for the colouration of materials 'ygiitnhthe dyes and the coloured materialsso ob- The nomenclature adopted throughout this speciflcationi's shown by the following formula for l :2: 3 :4-tetrahydronaphthopyridine.

The of the invention produce valuable I colourations, particularly blue to bluish-green shades, on ester or ethertextile mate- 7 rials, which are or good dischargeability and good fastnesstolight. Thenew'aaodyescanbeformed "on the cellulose ester. or ethertextlle materials, or-the'y can be made in, substance and then ap-' plied to the textile material; From the. point of view of dischargeability. it is of advantage to apply Y the formed dyes to the material.

wnue the dyestuffs mentioned a... be obtained by coupling a diaaotised amino-azo compound in 7-hydroxy'-l:2:3:4-tetra-. hydronaphthopyridine, capable of coupling'in the 6 position, e. g. the simple '7-'hydroxy-1:2:3:4-

'tetrahydronaphthopyridine, .n. has been found that particularly valuable dyes are obtained by using a 3 "l-dihydroxy-l :2 3 4-tetrahydronaphthop'yridine.

If desired the aminoazo compound and/or the 'l hydroxy -.l:2:3:4'- tetrahydronap'hthopyridine may contain other s'ubstituents, for example acidylamino, allryl, alko xy. hydroxyalkyl, rhydroxyethoxy groups or hal en atoms,;but when be used on ce lulose ester or ether there is obtained a series 110mm. "(mete-4st) from water-solubilising acidic groups, for example sulphonic or carboxylic acid groups.

The amino-azo compounds to be employed in accordance with the invention are preferably those in which the diazotisable amino group is in a para position to the azo group. 3.! e dihydroxy-1:2:3:4 -ytetrahydronaphthopyridine is coupled with 4 -amino-azo benzene, 4- amino- 3.2'- dimethylazobenzene, 4-amino-2z5- dimethoxyaaobenzene, benzeneazo alpha-naphthylamine and 4 amino -l.1'- azonaphthalene,

ofdyes which on cellulose ester orether materials give. particularly valuable shades varying from blue, through blue'thylaminoaaobenzene,

' S-methoxy-Ll'ebenzene-azo-naphthalene and 4 ish-green, to green. Examples of other aminoazo compounds which suitable for the invention are 2-methoxy-4-amino 4' dimethylaminoazo-w benzene, z-chlor-i-amino- -di- (beta-hydroxy) d-amino-z-acetylam'ino amino-2,-acetylamino-b beta-hydroxyethoxy-azobenzene.

The preierred aromatic amino-azo compounds -may,be prepared by coupling diazotised amines,

mexample aniline, toluidines. chloranilines and naphthylamines with primary aromatic amines capable of coupling in the para-position to the primary amino group, examples thereof being metatoluidine, para-xylidin'e, 3-amino- 4-methoxy 1 methylbenzene, 2:5-dimethoxy-aniline,

2:5 di(oxyethoxy) aniline, alpha naphthyl-- amine and l-amino-z-naphthol ethyl ether. Prima'ryv amines which do not couple readil with dlazo compounds inthe para-position to the primary-amino group, e. g. aniline and ortho-toluidineQcan be coupled in the form of their formaldehyde bisulphite compounds, the formaldehyde bis'ulphite residues being eliminated after coupling. J

The azodyes of the, invention can be applied 'to' cellulose ester or ether materials in the form or an aqueous dispersion or solution in organic solvents. Bath methods can be employed,'that is to say methods in which the materials are allowed to absorb the dye from a dispersion or solution of the latter in which'they are immersed.

Again mechanical impregnation methods may be used, the materials being impregnated with: a

- solutionor dispersion of the requisite amount of the azo dye; To this end padding or'printin methods may 'be employed. The mechanically impregnated material may then be aged orv steamed tocause theazo dye to enter the cellulose ester or ether material.

As, regards the procedure to be followed inrorm- .rrr.

Thus when ing the dyes on cellulose ester or ether materials, it is preferable to incorporate the diazo component in the material and then to efl'ect diazotisation followed by coupling with the coupling component in a separate bath. The diazo compound can be applied to the materials in the form of aqueous dispersions or solutions in organic solvents or by mechanical impregnation followed, if necessary, by ageing or steaming.

Those azo dyes of the present invention which are free from acidic water-solubilizing groups, e. g. sulphonic-and carboxy groups, while having substantive affinity for cellulose esters or ethers, have in general substantially no affinity for cellulose or animal fibres. Consequently such azo dyes when applied to mixed materials containing both cellulose, e. g. cotton or regenerated cellulose, and a cellulose ester or ether, will be taken up only by the latter, the cellulose component of the material remaining uncoloured. Thus by suitably colouring the cellulose component of such a mixed material with dyes resisting the cellulose esteror ether component, solid shades or two-colour effects can be readily obtained according to the components and dyes selected. The dye for the cellulose portion can be applied before or after the application of the dye for the cellulose ester or ether portion,

The new dyes are also of value for colouring cellulose ester or ether solutions, especially lacquers and spinning solutions. By shaping and setting such solutions in the form of filaments, straws, films, and the like, valuable coloured products can be produced. For example, coloured cellulose acetate filaments can be produced by dry spinning such coloured solutions.

The invention, so far as it relates to the colouration of materials, is particularly concerned with the production of coloured cellulose acetate prod ucts. The new dyes may, however, be used for the production of coloured products of other cellulose esters, for example cellulose propionate, butyrate or acetate-butyrate, or of cellulose ethers, for example methyl, ethyl or benzyl cellulose. Furthermore, the'new dyes may be employed for the colouration of materials having a basis of a super-polyamide, e. g., polyhexamethylene adipamide.

The invention is illustrated by the following examples, all parts being by weight:

Example 1 19.! parts of amino-azo benzene are diazotised in the usual manner with hydrochloric acid and sodium nitrite. After removalof the small excess of nitrous acid, the filtered solution is added to 252 parts of 3:1-dihydroxy-1:2:3:4-tetrahydronaphthopyridine hydrochloride dissolved in 600 parts of water. Coupling occurs rapidly, and the precipitated dyestufi is filtered, pasted with water and neutralized with sodium carbonate. The dyestuil' so obtained gives blue shades on cellulose acetate materials.

Similarly valuable dyes can be obtained by using 4-amino-2z5-dimethoxy azobenzene or benzene-azo-alpha naphthylamine instead of aminoazo benzene, or by using 7 -hydroxy- 1:2:324- tetrahydronaphthopyridine instead of the 3:7- dihydroxy compound.

. Example 2 10 parts of a 10% aqueous paste of benzeneazo-benzene-azo-3z'l-dihydroxy 1:2:324 tetrahydronaphthopyridine prepared as in Example 1 are dispersed in about 3,000 parts of water with Example 3 2 parts of 4-amino-2:5-dimethoxy-azo-benzene are dispersed in 4,000 parts of water with the aid of soap and Turkey red oil. 100 parts of cellulose acetate fabric are then dyed in this bath for 1 hours at -80" C., after which the fabric is washed off and diazotised for /2 hour in the cold in a 40:1 bath containing 5% sodium nitrite and 20% concentrated HCl on the weight of the goods.

The diazotized material is then washed 01f, en--- tered into a 40:1 developing bath containing 2% of 3:7-dihydroxy 1:2:3z4-tetrahydronaphthopyridine on the weight of the cellulose acetate, the bath being slowly warmed up to 60 C., and kept at this temperature for hour. After development the fabric is washed'oif well and soaped in a A g. p. 1. soap solution'for 20 minutes at 60 C.

The material is thus dyed in a greenish-blue shade of good light fastness.

Having described my invention what I desire to secure by Letters Patent is:

1. Process for the production of a disazo dye which comprises coupling a 7-hydroxy-lz2z3-4- tetrahydronaphthopyridine, capable of coupling in the 6 position, with a diazotized para-aminomono-azo compound of which the aryl radicles are selected from the group consisting of benzene radicles and naphthalene radicles.

2. Process for the production of a disazo .dye which comprises coupling a 3:7-dihydroxy 1 :2 :3 :4-tetrahydronaphthopyridine, capable of coupling in the 6 position, with a diazotized paraamino-mono-azo compound of which the aryl radicles are selected from the group consisting of benzene radicles and naphthalene radicles.

3. Process for the production of a disazo dye which comprises coupling 3:7-dihydroxy 1:223:4-

tetrahydronaphthopyridine itself with a diaz0-' tized aromatic para-amino-mono-azo compound of which the aryl radicles are selected from the group consisting oi. benezene radicles and naphthalene radicles.

4. Process for the production of a disazo dye which comprises coupling 3:7-dihydroxy 1:2:3z4- tetrahydronaphthopyridine in acid solution with diazotized amino-azo benzene.

5. Process for the production of a disazo dye which comprises coupling 3:7-dihydroxy 1:213:4- tetrahydronaphthopyridine in acid solution with diazotized 4-amino-3:2'-di-methyl-azo benzene.

6. Process for the production of a disazo dye which comprises coupling'sz'l-dihydroxy 1:2:3:4- tetrahydronaphthopyridine in acid solution with diazotized 4-amino-2 S-di-methoXy-azo-benzene.

7. A G-(arylazo-arylazo)-'7-hydroxy-1:2:3:4- tetrahydronaphthopyridine wherein the azo groups are in para position one to the other and the aryl radicles are selected from the group consilstingof benzene radicles and naphthalene radi- 0 es.

8. A 6 (arylazo-arylazo) 3:7 dihydroxy 1': 2 3 4-tetrahydronaphthopyridine wherein the azo groups are in para position one to the other and the aryl radicles are selected from the group consisting of benzene radicles and naphthalene radicles.

9. The blue disazo dye obtainable by coupling 3:7 dihydroxy 1:2'23z-tetrahydronaphthopyridine in acid solution with diazotized amlno-azo benzene.

10. The blue disazo dye obtainable by coupling 3:7 dihydroxy l:2:3:4 tetrahydronaphthopyridine in acid solution with diazotized 4-amino- 3:2'-dimethyl-azo benzene. I I I 11. The blue disazo dye obtainable by coupling 3:7 dihydroxy 1:2:3z4 tetrahydronaphthopyridine in acid solution 'with diazotized 4-amino- 2 5-dimethoxyazo benzene.

12. Textile materials colored with a disazo dye claimed in claim 7.

CHRISTOPHER STANLEY ARGYLE. 

